In the given figure, O is the centre of a circle. If $\angle AOB={100}^{\circ }and\angle AOC={90}^{\circ }then\angle BAC=?$

(a) ${85}^{\circ }$

(b) ${80}^{\circ }$

(c) ${95}^{\circ }$

(d) ${75}^{\circ }$

In the given figure, $O$ is the centre of a circle. If $\angle AOB =100^\circ$ and $\angle AOC =90^\circ$ , then $\angle BAC =?$

(a) $85^\circ$

(b) $80^\circ$

(c) $95^\circ$

(d) $75^\circ$

In the figure, AOB is a straight line. If $\angle AOC+\angle BOD={85}^0$, then$\angle COD$